Vacuum cleaner



Y 1940- G. w. ALLEN 2,2021788 VACUUM C EKNER Filed Oct. 11, 1938 I14 0677 $01" 650265 14/. ALJLEN by W141 JQM Watented May 28, 1940 UNITED STATES VACUUM CLEANER George W. Allen, Boston, Mass, assignor to B. F. Sturtevant Company, Boston, Mass.

' Application October 11, 1938, Serial No. 234,391

1 Claim.

This invention relates to vacuum cleaners and relates more particularly to vacuum cleaners of the manually propelled type.

Vacuum cleaners of the ordinary manually propelled type, for example, are usually provided with levers which may be adjusted by a hand or foot of the operator to raise or lower the cleaner nozzle as floor coverings of varying depth and porosity are encountered. For example, a vacuum nozzle moving over a relatively porous rug should be relatively close to the rug. If the same nozzle without adjustment were moved over'a less porous rug, the resistance to air flow would be too great, tending to overload the cleaner, to produce too great a suction and to cause the rug to adhere to the nozzle. In the past, in order to permit vacuum cleaners to operate most efliciently, it has been necessary for the operator to adjust levers to lower the cleaner nozzle as relatively porous rugs were encountered and to raise the nozzle when less porous rugs were encountered. Such adjustments have depended upon the operator's judgment with the result that in many cases nozzles set too high have been inefiectively used for cleaning relatively porous rugs, or nozzles set too low have been used for cleaning relatively non-porous rugs to overload the cleaner and to add to the difliculty of moving same.

This invention provides a vacuum nozzle which is automatically raised and lowered in response to changes in vacuum caused by varying resistances in the material being cleaned, to maintain a desired predetermined suction at the material being cleaned and to maintain accordingly, the cleaner in the most efllcient operating condition. As relatively porous floor coverings are encountered, the nozzle lowers itself to maintain the desired suction. Then as less porous floor coverings are encountered, the nozzle raises itself to main tain the desired suction. 1

The invention will now be described with reference to the drawing, of which: Fig. l is a profileview with 'a portion brokenaway, of a vacuum cleaner embodying this invention; l 1 1 5 Fig. 2 is a plan view of the bottom of 'the cleaner of Fig. l, and

Fig. 3 is a sectional view along the lines 3-4 of I Fig. 2.

includes the stream-lined casing 5 which terminates at its front end in the nozzle cover 6 and at its rear end in the connection I to the dust receiving bag 8. The usual electric motor 9 drives the usual blower wheel ill for providing the it necessary suction. v

The cleaner nozzle H includes the converging walls l2 between which the air into the cleaner enters. The nozzle H has a rear extension ll forming the lower portion of the inlet passage to o the wheel Ill. The extension H! has the rear hinge portion ll which is hinged at ii to the cleaner frame. 7

The nozzle Ii and its rear extension II is connected to the nozzle cover 6 and to the lower 2 housing of the wheel Ill by the flexible material 26 which, for example, may be rubber and the purpose of which, is freely to permit up and down movement of the nozzle H about its hinge i5, while at the same timeit forms such an ei- 30 fective air seal that no air can enter the cleaner except at the nozzle lips l9 formed by the lower portions of the nozzle walls I2.

The rotary sweeper brush cylinder I6 is attached by the screws II to the end walls ll of the nozzle and is adapted to be rotated during operation of the cleaner, by the belt l9 driven by the motor 9.

The converging walls l2 oi the nozzle II and to some extent the rear extension l3 of the nozzle, 5; act during the operation of the cleaner as a suction responsive diaphragm movable through the suction exerted by the blower wheel l0. As the resistance to air flow through the nozzle increases due to its movement were thicker or more closely woven floor covering, the suction in the nozzle increases and this increase in suction acting upon the lower walls of the nozzle, lifts the nozzle upwardly to provide a greater spacing between the nozzle lips and the material being cleaned, to reduce the air resistance and the suction to normal. When the nozzle passes from a closely woven floor covering onto one more porous or onto a bare floor, the weight of the nozzle becomes greater than the suction force .6

The embodiment of the invention illustrated-19 acting upwardly upon its walls and the nozzle is automatically lowered to restrict the air inlet area and to conformably increase the air resistance and the suction to normal.

The brush cylinder it? in the embodiment illustrated is lifted and lowered with the'nozzle and this is preferred. The nozzle could of course move independently of the brush cylinder when brush cylinders are used. or could be used without a sweeper cylinder.

In the annexed claims the term "vacuum cleaner refers to what'are also known as vacuum sweepers.

While one embodiment of the invention has been described for the purpose of illustration. it should be understood that the invention is not limited to the exact apparatus and arrangement of apparatus illustrated and described since many departures therefrom may be suggested by those skilled in the art without departing from the in vention.

What is claimed is:

In a vacuum cleaner having a blower wheel, a lower housing having substantially horizontal flanged walls extending below said wheel. a suction nozzle including a rcarwardly extending plate having a central portion having a large area extending underneath said wheel and having upper flanged walls parallel to said walls ll said housing. a nozzle cover having Hanged lower 3.118 extending substantially parallel to and normally spaced from the upper walls of said nozzle. a flexible diaphragm extending completely around said nozzle and extending between and attached to said flanged walls. the walls of said nozzle. said cover. said housing and said diaphragm forming an air passage connecting with said Wheel, said diaphragm permitting said nozzle to be moved towards said cover in response to suction on said nozzle walls. said housing having a large lower opening between said first mentioned flanged walls. (XtEllfllllL' above said plate whereby said plate provides a relatively large area for positive actuation under a small pressure differential. and means pivoting the rear portion of said plate to said housing.

GEORGE W. ALLEN. 

